Many residential and light commercial structures are built on concrete foundation walls which are formed by pouring concrete into a system of forms that have been erected in an excavated trench. After the concrete has cured sufficiently, the forms are stripped from the concrete and the trench is filled around the wall. Typically, the base of each foundation wall is supported on a concrete footing, which is slightly wider than the thickness of the wall itself. Ideally, the centerline of the wall is aligned with the centerline of the footing. The footing spreads the load of the structure over a greater area and prevents uneven settling of the foundation.
In the past, the footing at the base of the wall was poured before the wall was poured. The forms for the footing were erected, and concrete was poured in the form. After the concrete footing had sufficiently cured, the forms for the footings were stripped and removed, and separate wall forms were erected. After the wall section had been poured and cured, the wall forms were removed and the foundation wall is complete.
Typically, each of the form sections are pre-treated with an oil based releasing agent prior to pouring the concrete, which makes it much easier to strip and remove the forms from the cured concrete. Unfortunately, the releasing agents frequently contaminate the top surface of the footing section, thus preventing the later poured wall section from bonding properly to the footing. As a result, some portions of the foundation wall are weaker than other portions, and the foundation wall is more likely to leak and is more prone to cracking and uneven settling. Accordingly, modular form systems have been developed that allow the footing and the wall to be poured simultaneously.
The combination footing/wall form systems presently available suffer from a number of inherent drawbacks. First, in order for the combined footing/wall forms to be labor efficient, the footing form and the wall form must be connected into a panel, and then each panel must be connected to an opposing panel by a series of cross ties in order to form the concrete receiving cavity in between the panels. The prior art opposing panels must be connected to each other after the panels have been placed in the trench, which offers little space for the workers to maneuver. Another drawback with these combination from systems is that, due to hydrostatic pressure, the form is likely to lift off the ground when the concrete is poured. Accordingly, either the form must be secured to the ground with ground screws to anchor the form or the top of the footing section must be sloped. Ground screws are difficult and time consuming to install, and sloped footings violate most local building codes.
An improved modular wall forming system according to the present invention allows the footing and wall to be poured simultaneously, and permits the formation of a footing with a flat top surface which meets most local codes. The modular wall forming system according to the present invention allows two opposing spaced apart wall forming members to be pre-assembled and put in place as a single unit, so that each complete unit need only be connected to an adjacent unit prior to pouring the concrete. The modular wall forming system of the present invention does not require labor intensive ground anchors and will not sink into the ground.